CN203151239U - Wireless energy transmission system - Google Patents

Abstract

The utility model provides a wireless energy transmission system. The energy transmission mode of the wireless energy transmission system of the utility model is different from a traditional energy transmission mode which adopts an air-core coil as a carrier to perform energy transmission. The wireless energy transmission system includes a transmitting end and a receiving end; the transmitting end comprises a signal generator power source and a transmitting coil; the receiving end includes a receiving coil; and iron cores are arranged in the transmitting coil and receiving coil. The wireless energy transmission system of the utility model is advantageous in effective improvement of the efficiency of existing wireless energy transmission systems, simple operation, no need for large-scale modification of energy transmission lines, concise and reasonable design, safe and convenient usage, no harm to people and other living things, convenient operation, great enrichment of theoretical and experimental evidences of relevant specialties, great practicality, innovativeness and safety.

Description

A kind of wireless energy transfer system

Technical field

The utility model relates to the radio energy transmission technique field, especially relates to a kind of wireless energy transfer system that iron core improves efficiency of transmission that adds.

Background technology

From the energy transmission mechanism, existing wireless energy transmission technology mainly is divided into following three classes: 1. electromagnetic radiation formula wireless energy transmission technology claims the far field Radio Transmission Technology again.This technology is transmitted signal as radio frequency and is directly utilized electromagnetic wave to carry out the energy transmission; 2. non-radiative induction wireless energy transmission technology belongs to the near field Radio Transmission Technology, and its theoretical foundation is the law of electromagnetic induction.3. non-radiative electromagentic resonance formula wireless energy transmission technology also belongs to the near field Radio Transmission Technology, according to the transmission medium difference, can be divided into magnetic resonance wireless energy transmission technology and electric field resonance wireless energy transmission technology.Such technology utilization has the resonant body of identical resonance frequency, when separated by a distance, is that media intercouples with magnetic field or electric field, produces resonance, realizes the transmission of energy.This belongs to revolutionary technology in the wireless energy transfer.

Resonance manifold type wireless energy transfer proposes prior to the research team by MIT physics professor Marin Soljacic in 2006.This team is in experiment, and adopting two radiuses is 30cm, quality factor q=950 helical coils, when operating frequency is about 9.9MHz, has successfully lighted a 60w bulb apart from 2m as the coil that transmits the energy resonant body, and energy transmission efficiency is 40-60%.This experiment of MIT has started the tide of wireless energy transfer research.

MIT experiment and afterwards mostly in the experiment, all be with air core coil as carrier, the mode by magnetic coupling resonance realizes wireless energy transfer.

The utility model content

On research forefathers theoretical foundation, the utility model proposes a kind of wireless energy transfer system that uses iron core to improve wireless energy transmission efficiency.

The technical solution of the utility model is a kind of wireless energy transfer system, comprises transmitting terminal and receiving terminal, and transmitting terminal comprises the signal generator power supply and send coil that receiving terminal comprises receiving coil, sends in coil and the receiving coil and is provided with iron core.

And transmission coil and receiving coil are evenly close around lead, and the conductor cross-section of coiling is circular.

And the lead that sends coil and receiving coil adopts the multiply enamelled wire.

And described iron core adopts ferrite.

The utility model can improve present wireless energy transfer system efficient effectively, and easy and simple to handle the needs energy transmission line road is changed on a large scale, design is succinct rationally, what injury is safety easy to use do not have to people and biology.The utility model provides a kind of method of new raising energy transmission efficiency as wireless energy transfer system, and theory and the experiment evidence of relevant speciality are greatly enriched in simple operation, have good practicability, have embodied the requirement of novelty and fail safe.

Description of drawings

Fig. 1 is the circuit theory diagrams of the utility model embodiment.

Fig. 2 is the systematic survey circuit diagram of the utility model embodiment.

Embodiment

Describe technical solutions of the utility model in detail below in conjunction with drawings and Examples.

Along with the wireless energy transfer system development, more and more scholars and expert move to sight on the wireless energy transfer system of middle distance.The wireless energy transmission technology of middle distance can not only transmit energy relatively efficiently, and what harm people and biology are not had.

As shown in Figure 1, the wireless energy transfer system that embodiment provides comprises transmitting terminal and receiving terminal, and transmitting terminal comprises the signal generator power supply, sends coil, and receiving terminal comprises receiving coil and load.The equivalent electric circuit of transmitting terminal comprises signal generator power supply AC, the internal resistance of transmission coil, the transmission coil inductance of series connection and sends coil capacity that the equivalent electric circuit of receiving terminal comprises receiving coil internal resistance, receiving coil inductance and the receiving coil electric capacity of series connection.Wherein K12 represents the coupling parameter between coil, sends coil capacity and receiving coil internal resistance and equates to be R, sends coil capacity and receiving coil inductance and equates to be L, sends coil capacity and receiving coil electric capacity and equates to be C.Send in coil and the receiving coil and be provided with iron core.Being characterized as of coil is evenly close around lead, and the per share conductor cross-section of coiling is circular.

Add the wireless energy transfer system behind the iron core, adopt the mode of resonance coupling to carry out the energy transmission.The system of embodiment comprises that the signal generator model is RIGOL mutual inductor (the transmission coil and the receiving coil that add iron core), the subloop of the major loop of capacitor and capacitor and load, energy delivered is lighted load light with the resonance inductive coupling of coil, and bright degree is better than air core coil, thereby has realized the transmission of energy and improved the efficient of energy transmission.

To increase the inductance that magnetic permeability increases coil in order connecting, and to obtain high energy transmission efficiency to improve quality factor, coil can adopt the enamelled wire of multiply, and per share cross section all is circular.

For the purpose of implementing reference, based on wireless energy transfer system, utility model further provides the test circuit of determining how to add iron core.As shown in Figure 2, test circuit comprises transmission loop, receiving loop and oscilloscope, sends signal generator, transmission coil and transmission electric capacity that the loop comprises series connection, and signal generator links to each other with oscilloscope; Receiving loop comprise series connection receiving coil, receive electric capacity and load, load two ends bulb in parallel is connected oscilloscope after receiving coil and the reception capacitances in series.

The test circuit of concrete the utility model embodiment mainly comprises with the lower part:

1. signal generator part (linking to each other with oscilloscope), its model is RIGOL, for whole system provides voltage source, come to provide operating power and energy for whole system to main circuit power supply by voltage source, so this signal generator is equivalent to input signal, but the power of input signal is the used up power of voltage source power subtraction signal generator internal resistance in the calculating of back.By a voltage source is provided for whole system, through measurement and the record of filter, calculate the power in two loops, provide a good approach for surveying efficiency of transmission.

2. mutual inductor (the transmission coil and the receiving coil that add iron core), this is the key component of the main innovation of the utility model.What all adopt in experiment in the past and the research is air core coil, the utility model adopts is the coil that adds behind the iron core, come the relative variation of observation oscilloscope input signal and output signal by the quantity situation that changes iron core in two coils successively, realized the transmission of major loop and subloop coil energy by the resonance coupling of two coils.

3. the subloop part of the major loop of capacitor and capacitor and load, by observation oscilloscope input signal and variation of output signals, the relation of input signal and output signal when determining maximum transmitted efficient is in order to the relation of clear and definite power output and input power.Major loop mainly provides transmitted power, and subloop mainly provides received power, can obtain comparatively accurate result by oscillographic record.

Below each several part provided describe in detail in order to implement reference:

1. mutual inductor (the transmission coil and the receiving coil that add iron core)

Send the affiliated major loop of coil, subloop under the receiving coil.According to damping ratio formula or quality factor formula:

$\mathrm{\ξ}=\frac{R\sqrt{C}}{2\sqrt{L}}$ $Q=\frac{1}{R}\sqrt{\frac{L}{C}}---\left(1\right)$

(wherein R, C, L are followed successively by and send coil resonance resistance, resonant capacitance and resonant inductance).Because high quality factor Q is conducive to the raising of efficiency of transmission, so be under the definite value situation about remaining unchanged at resonant resistance and resonant capacitance, have only the coil inductance of raising L, just can reduce damping ratio ξ or increase quality factor q, just can make energy transfer efficiency η more strong.

The inductance L of helical coil can be used following equation expression:

$L=N^{2}r{\mathrm{\μ}}_0[\ln \left(\frac{8r}{a}\right)-1.75]---\left(2\right)$

Wherein, μ 0 is air core coil magnetic permeability (being equivalent to permeability of vacuum), and r is the radius of helical coil, and N is the number of turn of helical coil, and a is the radius of winding wire.If in helical coil, add the core material of some high magnetic permeability, magnetic permeability almost is linear to be increased, magnetic permeability can increase up to ten thousand times like this, resonant inductance also can increase up to ten thousand times, calculate back Q through the quality factor formula and also can increase hundreds of times, so just improved system transmissions efficient more effectively.So add iron core wireless energy transmission efficiency there is considerable influence.

Often adopt silicon steel as core material in the electrician trade, but it only limits to power frequency f=50Hz, and its can increasing at inside generation eddy current along with frequency of utilization.The generation of eddy current, one side can cause the iron core temperature to raise and then damage coil insulation material, and the extra energy of eddy-current heating meeting loss reduces the efficient that energy transmits on the other hand.The current density of eddy current is not more big the closer to the conductive surface place (being even distribution), and the effect that this eddy current tends to concentrate on conductive surface is called skin effect.Again by formula

$R=\mathrm{\ρ}\frac{l}{S}---\left(3\right)$

Wherein R is the resistance of helical coil, and ρ is the resistivity (this experiment is selected the higher brass of resistivity for use as conductor material) of winding wire, and l is the total length of coil, and S is the cross-sectional area of lead.

Because the existence of eddy current makes the application of silicon steel aspect high frequency be restricted, what obtain now developing rapidly is a kind of nonmetal magnetic material-ferrite.It is formed by the powder technique of the metal oxide (as NiO, ZnO, MnO etc.) of di-iron trioxide (Fe2O3) and other divalence, belongs to the oxidate magnetic material of little magnetic loss, low-coercivity, high magnetic permeability, high resistivity and high saturated magnetic induction.Its key character also can have high magnetic permeability when higher frequency.

Employing can obtain high magnetic permeability, little coercive force, little remanent magnetism, again can be when frequency be higher the ferrite of operate as normal as core material.

The high numerical value of ferrite magnetic core material length and width that adds in air core coil is 10cm * 6cm * 6cm.

2. the electric signal generator model is the RIGOL part

The signal generator model is the EE1642B1 part, for whole system provides voltage source, comes for whole system provides operating power and energy to main circuit power supply by voltage source, so this signal generator is equivalent to input signal.

3. the subloop part of the major loop of capacitor and capacitor and load is in order to the relation of clear and definite power output and input power;

Select for use the enamelled wire of multiply to carry out the making of coil in this experiment, the number of turn is 10 circles, the radius 15cm of every circle, vertical range between homemade two coils is 80cm, wherein the ceramic condenser capacity selected for use of electric capacity is less, select 15pF electric capacity for use, its resistance of signal generator is fixed in this research contents, because average power signal P-U ²/ R, the tolerance of power just can be decided by voltage of signals U so, chooses the voltage of signals effective value at this and analyzes to replace to the energy spectrometer of signal takes place.

At first the circuit in the accompanying drawing 2 is analyzed, can be obtained at receiving terminal:

$\mathrm{Pi}=\frac{\mathrm{Vs}-\mathrm{Vi}}{\mathrm{Rs}}\×\mathrm{Vi}$ $\mathrm{Po}=\frac{{\mathrm{Vo}}^2}{\mathrm{Ro}},$

Wherein Vs represents not connect the output voltage at signal generator two ends when sending coil, Vi represents to connect the output voltage at signal generator two ends when sending coil and receiving coil, Vo vice loop load two ends output voltage, Rs and Ro represent the resistance of generator self internal resistance and subloop load respectively; Pi and Po represent to send the power output at coil and receiving coil (load) two ends respectively.

Can obtain efficiency of transmission:

$\mathrm{\η}=\left(\frac{P_o}{P_i}\right)\×100\%$

The running of whole system now is described as follows:

At first signal generator provides power supply to major loop in the system, and by the coupling of iron-core coil, energy is delivered to subloop, makes the load operate as normal of subloop.Obviously improved the energy transmission efficiency of air core coil.

Specific embodiment described herein only is that the utility model spirit is illustrated.The utility model person of ordinary skill in the field can make various modifications or replenishes or adopt similar mode to substitute described specific embodiment, but can't depart from spirit of the present utility model or surmount the defined scope of appended claims.

Claims (4)

1. wireless energy transfer system is characterized in that: comprise transmitting terminal and receiving terminal, transmitting terminal comprises the signal generator power supply and sends coil that receiving terminal comprises receiving coil, sends in coil and the receiving coil and is provided with iron core.

2. according to the described wireless energy transfer system of claim 1, it is characterized in that: transmission coil and receiving coil are evenly close around lead, and the conductor cross-section of coiling is circular.

3. according to the described wireless energy transfer system of claim 2, it is characterized in that: the lead that sends coil and receiving coil adopts the multiply enamelled wire.

4. according to claim 1 or 2 or 3 described wireless energy transfer systems, it is characterized in that: described iron core adopts ferrite.

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